Instrument Simulations and Virtual Experiments

The NexMaP simulation effort revolves around two world class software packages; McStas (neutron scattering) McStas homepage and McXtrace (X-rays) McXtrace homepage. The packages are designed to simulate any and all neutron and X-ray scattering instruments and experiments.

McStas and McXtrace are:

  • Open Source (GPL)
  • Multiplatform
  • Fast and Scalable
  • Extendable 


McStas is used at all major neutron facilities around the world; Research reactors and Spallation sources alike.

McXtrace is used at X-ray scattering facilities around the world and is the chosen optics simulation tool for the ATHENA telescope (ESA).


We are actively working with groups within DTU and around the world for new developments and validation/benchmarking efforts:

McStas and McXtrace Workshops

The simulation group makes it a priority to hold and attend workshops/tutorials and conferences - in an effort to help our users reach their goals and gain valuable insights in new instrument developments.

Current Project Highlights

NEXMAP is leading the design effort of the BIFROST instrument@ESS. An effort which involves lots of CPU-hours of McStas-simulations.

In collaboration with DTU SPACE and ESA, NEXMAP develops digital models of the optics of the ATHENA Space X-ray telescope.

The next step in High Performance Computing is to run scientific software on GPUs. The McStas/McXtrace-team is researching and developing tools for harnessing this power.

McXtrace: Current projects and main themes

Student Projects

We are happy to offer a range of student projects that can easily be tailored to your interests.

Find the current listing in the Project Bank at DTU

Any of these projects can be tweaked to fit specific requirements.

Projects can be tailored to almost any level, harnessing the modular nature of McStas/McXtrace, either as combinations with experiments or purely theoretical exercises.

Current Examples:

  • The effect of dust contamination on Mirror performance.
  • General functional series expansion to enhance source sampling.
  • Calibration of X-ray source models vs Experiments.
  • The effect of Scattering from mirror support structures on telescope performance


Erik Bergbäck Knudsen
Research cooperation
DTU Physics


Peter Kjær Willendrup
Senior Research Engineer, Special Consultant
DTU Physics
+45 21 25 46 12